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doc: Remove documentation for microkernel command packet sets

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Update semaphore documentation to remove mention of command
packet sets, which no longer exist.

Change-Id: I19303f7f497b7d8299723d01c91ae4f4513162f0
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
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Allan Stephens 2015-10-29 10:54:33 -04:00 • committed by Anas Nashif
commit 7ed2678916
1 changed files with 0 additions and 47 deletions
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doc/kernel/microkernel/microkernel_semaphores.rst
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@ -19,22 +19,6 @@ is taken. However, a semaphore cannot be taken if it is unavailable
Semaphores may be given by tasks, fibers, or ISRs.
.. note::
When a semaphore is given by a fiber or an ISR the caller must provide
a statically-allocated command packet for the microkernel server fiber
to use, since the kernel cannot create one on the caller's stack as it
does when the semaphore is given by a task. In cases where the fiber
or ISR can give the semaphore again before the microkernel server finishes
processing the earlier request the caller must provide a separate command
packet for each concurrent give operation.
The kernel provides the :c:macro:`CMD_PKT_SET_INSTANCE()` API to allow
a fiber or ISR to define a *command packet set* containing one or more
command packets. The :c:macro:`CMD_PKT_SET()` API is then used to reference
the command packet set when giving a semaphore;
see :ref:`isr_gives_semaphore`.
Semaphores may only be taken by tasks. A task that attempts to take
an unavailable semaphore may choose to wait for the semaphore to be given.
Any number of tasks may wait on an unavailable semaphore simultaneously;
@ -143,37 +127,6 @@ is available for processing by a consumer task.
...
}
.. _isr_gives_semaphore:
Example: Giving a Semaphore from an ISR
=======================================
This code uses a semaphore to indicate that a unit of data
is available for processing by a consumer task.
.. code-block:: c
/*
* reserve 2 command packets for semaphore updates
*
* note: this assumes that input data arrives at a rate that allows
* the microkernel server fiber to finish the semaphore give operation
* for data item "N" before the ISR begins working on data item "N+2"
* (i.e. data arrives in bursts of at most one unit)
*/
static CMD_PKT_SET_INSTANCE(cmd_packets, 2);
void input_data_interrupt_handler(void *arg)
{
/* save data item in a buffer */
...
/* notify task that an additional data item is available */
isr_sem_give(INPUT_DATA, &CMD_PKT_SET(cmd_packets));
...
}
Example: Taking a Semaphore with a Conditional Time-out
=======================================================